Science Advisory Report  2016/013

Assessment of Newfoundland and Labrador (Divisions 2HJ3KLNOP4R) Snow Crab

Summary

Divisions 2HJ3KLNOP4R

• Landings most recently peaked at 53,500 t in 2009 and have since gradually declined to 47,000 t in 2015. Divs. 3LNO have accounted for a steadily increasing percentage in recent years, from about half in 2009 to 80% in 2015.
• The overall exploitable biomass has declined since 2013 to its lowest observed level.
• Overall, recruitment has recently declined. It was at or near its lowest observed level in all divisions in 2015. It is expected to decline further in the next 2‑3 years, as the pre-recruit biomass index was at its lowest observed level in all divisions in 2015.
• A small pulse of young crabs emerged during 2013‑14 which could contribute to modest improvements in recruitment in some divisions in about 5 to 7 years. However, a warm oceanographic regime coupled with relatively low abundance of young crabs for the past decade suggests overall weak recruitment in the long-term.

Divisions 2HJ

• Landings have remained relatively low at less than 2,000 t since 2011. Meanwhile, effort has been substantially reduced and been at its lowest level during the past three years.
• Catch per unit of effort (CPUE) has increased throughout the divisions since 2012.
• The trawl and collaborative post-season (CPS) trap survey-based exploitable biomass indices both increased sharply in 2014. The trawl index returned to a relatively low level in 2015 but the CPS trap survey index suggests the biomass remains unchanged on primary fishing grounds.
• Recruitment increased sharply to a recent high in 2014 but subsequently decreased to a relatively low level in both the trap and trawl surveys in 2015.
• Short-term recruitment prospects appear poor. With the exception of 2014 the pre-recruit biomass index has been relatively low in recent years and was at its lowest level in 2015. The thermal habitat index suggests further deterioration of recruitment potential over the next 2‑3 years.
• The pre-recruit fishing mortality index was very low in 2015.
• The exploitation rate index peaked in 2012 but since decreased to about its lowest level in 2015. Status quo removals in 2016 would once again increase the index to a level similar to recent norms.

Division 3K

• Landings declined by 52% since 2008 to 7,200 t in 2015, their lowest level in two decades. Meanwhile, effort has declined by 35% and been near its lowest level for the past three years.
• CPUE declined by 55% from 2008 to 2011 and has since changed little, remaining near a historic low and reflecting trends throughout most of the division.
• The post-season trawl and trap survey exploitable biomass indices both declined since 2008 to their lowest observed levels. Both indices decreased by a third from 2014 to 2015, reflecting decreases throughout the division.
• Recruitment is at or near time series lows throughout the division.
• Recruitment is expected to decline further in the short term with all trawl and trap pre-recruit indices near historical lows during the past three years. The thermal habitat index suggests further deterioration of recruitment potential over the next 2‑3 years.
• The pre-recruit fishing mortality index was relatively low from 2005‑13 but has since increased to a recent high. The exploitation rate index was about average during 2014 and 2015.
• Maintaining the current level of removals would increase the exploitation rate in all management areas in 2016 with the overall trawl survey exploitation rate index increasing to its highest level in a decade and second highest level in the time series.

Divisions 3LNO Offshore

• Landings increased gradually since 2009 to a historic high of 28,750 t in 2015. Effort declined considerably from 2011‑13 but increased slightly in the past two years.
• Overall CPUE most recently peaked in 2013. It declined slightly in the past two years but remains high.
• The trawl survey of exploitable biomass shows the resource has become increasingly localized into portions of Div. 3L, with the biomass index at its lowest observed level in 2015. The CPS trap survey index suggests the density of exploitable crabs remains unchanged on the primary fishing grounds.
• Overall recruitment has declined since 2012 to be near its lowest level, reflecting trends throughout most of the divisions.
• Recruitment is expected to decline further in the short term (2‑3 years). The trawl survey pre-recruit biomass index has steadily declined since 2009 to a historic low while the CPS trap survey index is at or near its lowest observed level in most surveyed areas.
• The pre-recruit fishing mortality index has remained relatively low since 2008 while the exploitation rate index changed little from 2010‑14.
• Maintaining the current level of fishery removals would substantially increase the trawl survey exploitation rate index to a new high in 2016.

Division 3L Inshore

• Landings increased gradually since 2012 to a historic high of 8,400 t in 2015 while effort changed little.
• Overall CPUE has been near its highest level for the past four years. This reflects trends in Crab Management Areas (CMAs) 6A, 6B, and 6C, while other CMAs have been declining during the past two years.
• The overall post-season trap survey exploitable biomass index increased steadily from 2011‑14 to its highest levels in the time series. However, it decreased in all areas in 2015 and returned to the 2011 level.
• Overall recruitment has declined gradually since 2010 to its lowest observed level.
• Recruitment is expected to decline further in the short-term (2‑3 years). Pre-recruit biomass surveys from CPS and Fisheries and Oceans (DFO) trap surveys throughout the division have been at or near their lowest levels in a decade during the past two years.
• The overall post-season trap survey-based exploitation rate index changed little from 2005‑15.
• Maintaining the current level of fishery removals would increase the exploitation rate index in all areas in 2016.

Subdivision 3Ps

• Landings declined from a recent peak of 6,700 t in 2011 to 2,500 t in 2015. Effort reached a historic high in 2014 and decreased slightly in 2015, when only 60% of the Total Allowable Catch (TAC) was taken.
• CPUE has steadily declined since 2009 to a record low in 2015, reflecting declines throughout this subdivision in recent years.
• The trawl survey exploitable biomass index declined by 78% since 2009 to a time series low in 2015. The CPS trap survey was not conducted in most areas in 2015 due to poor resource status, thus no biomass index is available from that survey.
• Overall recruitment has declined since 2009 to its lowest observed level.
• Recruitment is expected to remain low in the short term (2‑3 years) as the trawl survey pre-recruit biomass index has been at its lowest levels for three consecutive years.
• The pre-recruit fishing mortality index and the exploitation rate index have both been at or near their highest observed levels during the past three years.
• Maintaining the current level of fishery removals would result in a continued high exploitation rate in 2016.

Divisions 4R3Pn

• Landings increased from a historic low of 190 t in 2010 to between 750‑900 t since 2012. Effort has been relatively unchanged since 2012.
• Overall CPUE has remained near its highest observed level in the past four years but there is considerable variability among management areas.
• The post-season trap survey exploitable biomass index has been unchanged for the past three years.
• Overall recruitment has been low for the past two years.
• Recruitment prospects appear relatively weak for the next 2‑3 years. The CPS trap survey pre-recruit index has been relatively low since 2012.
• The post-season trap survey-based exploitation rate index has varied since 2005 and was about average in 2015.
• Maintaining the current level of fishery removals would result in little change to the exploitation rate index in 2016.

This Science Advisory Report is from the February 22‑24, 2016, Newfoundland and Labrador Snow Crab Assessment. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

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